1. Technical Field
The present invention relates to a telephone hook switch and, more particularly, to a telephone hook switch using a non-contact capacitive sensor and a telephone using the same capable of overcoming a structural limitation as well as improving inner space usability of the telephone by employing a non-contact capacitive sensor as a hook switch for generating a call signal or a waiting signal for the telephone, instead of a mechanical construction.
2. Description of the Related Art
In general, modern society is called a third revolutionary era, i.e., an information revolution era. Human beings face the information revolution era via the agricultural revolution era and through the industrial revolution era. There are several information transmission means for representing the information revolution era. However, the most representative one is the telephone.
The telephone is operated by a series of operations, such as holding up or down a telephone receiver arranged on a main body of the telephone. The telephone includes a main body connected to a remote office line, a telephone receiver for transmission and reception, and a connection line connecting the main body and the telephone receiver.
In the main body, a mounting unit on which the telephone receiver is mounted is provided on one side of the upper surface, a keypad having a number of buttons for performing a function of the telephone is arranged on another side of the mounting unit, and a speaker for producing a receive signal of the telephone is mounted on a predetermined portion of the upper surface of the main body.
A hook switch for identifying whether a user is making a call (ON state) or not (OFF state) is provided on the mounting unit. When the user does not wish to make a call, the main body remains in a ready state, receives any call signal transmitted via the office line, and informs the user of the call signal through the speaker.
A plunger and the aforementioned hook switch are provided to implement ON/OFF functions in the telephone. The telephone hook switch has the shape of the telephone main body. Furthermore, under the mounting unit on which the telephone receiver is mounted, there are provided a plunger movably hinge-connected and elastically supported by a spring so as to protrude outside the mounting unit, the hook switch ON/OFF switched according to a pivoted state of the plunger, and a printed circuit board for switching a power supply path according to whether the contact of the hook switch is open or closed so as to change the ON/OFF state of the telephone.
When the telephone receiver is mounted on the mounting unit, pressure is applied by the telephone receiver to the plunger arranged and protruding from the mounting unit so that the plunger pivots inside the main body. The pivoting plunger changes the contact state of the hook switch so that the telephone remains OFF and awaits a call signal through the office line.
Furthermore, when the user lifts the telephone receiver off the mounting unit in order to make a call, the pressure applied to the plunger by the telephone receiver is removed, and the plunger returns to its initial state by means of a spring that elastically supports the plunger. As the plunger returns to its initial state, the contact of the hook switch switched by the plunger is switched again so that the telephone receiver remains in the ON state.
However, the telephone using the plunger and the hook switch as described above has a problem in that additional processes, such as assembling the plunger and the hook switch into the main body of the telephone and producing parts, are required. This increases the manufacturing cost of the telephone. In addition, there is another problem in that, when the elasticity of the spring that elastically supports the plunger is degraded due to frequent use and the hook switch does not operate well, ON/OFF operations of the telephone are not performed smoothly.
In addition, the weight of the telephone receiver should be more than a certain value in order to operate the plunger, and a space for accommodating the plunger and the hook switch operated by the plunger in the main body of the telephone, and a space for operating the plunger, are necessarily required. This limits the shape and the use of an inner space of the telephone main body. Therefore, there is a limitation imposed on design of the shape of the telephone.
The following patents are considered to be generally pertinent to the present invention, but are burdened by the disadvantages set forth above: U.S. Pat. No. 6,865,269 to Li et al., entitled METHOD AND APPARATUS FOR SWITCH HOOK DETECTION, issued on Mar. 8, 2005; U.S. Pat. No. 6,687,371 to Fischer et al., entitled MAINTAINING AN OFF-HOOK CONDITION DURING A CALL BRIDGE, issued on Feb. 3, 2004; U.S. Pat. No. 6,301,344 to Meyer et al., entitled INTELLIGENT PUBLIC TELEPHONE SYSTEM AND METHOD, issued on Oct. 9, 2001; U.S. Pat. No. 6,160,885 to Scott et al., entitled CALLER ID CIRCUIT POWERED THROUGH HOOK SWITCH DEVICES, issued on Dec. 12, 2000; U.S. Pat. No. 5,485,509 to Oliver, entitled TELEMETRY DEVICE INCLUDING A DYNAMIC OFF-HOOK DETECTOR, issued on Jan. 16, 1996; U.S. Pat. No. 4,613,730 to Fechalos et al., entitled ELECTRONIC TELEPHONE WITH FEATURE ACCESS AND SPEED DIALING INCLUDING LOOP BREAKS, issued on Sep. 23, 1986; and U.S. Pat. No. 4,528,425 to Melindo et al., entitled METHOD OF AND CIRCUITRY FOR DETECTING, AT A TELEPHONE EXCHANGE, THE LIFTING OF A SUBSCRIBER'S HANDSET IN RESPONSE TO RINGING CURRENT EMITTED BY THE EXCHANGE, issued on Jul. 9, 1985.